U.S. patent application number 15/015544 was filed with the patent office on 2016-08-25 for air cleaner and image forming device with air cleaner.
This patent application is currently assigned to Konica Minolta, Inc.. The applicant listed for this patent is Konica Minolta, Inc.. Invention is credited to Takumi MICHIBATA, Yoshinori OHNO.
Application Number | 20160246254 15/015544 |
Document ID | / |
Family ID | 55696839 |
Filed Date | 2016-08-25 |
United States Patent
Application |
20160246254 |
Kind Code |
A1 |
MICHIBATA; Takumi ; et
al. |
August 25, 2016 |
AIR CLEANER AND IMAGE FORMING DEVICE WITH AIR CLEANER
Abstract
An air cleaner having a filter, causing air to pass through the
filter and discharging the filtered air. The air cleaner includes:
an air duct having an inlet via which air is received and an outlet
facing a first part of a main surface of the filter and via which
the received air is output towards the first part of the main
surface; a fan causing air to be received by the air duct via the
inlet, to be output from the air duct via the outlet, and to pass
through the filter; and a flow distributer disposed between the
outlet and the filter. The flow distributer changes a direction of
flow of air output from the air duct from towards the first part of
the main surface to towards a second part of the main surface of
the filter that does not facing the outlet.
Inventors: |
MICHIBATA; Takumi;
(Toyokawa-shi, JP) ; OHNO; Yoshinori;
(Toyokawa-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Konica Minolta, Inc. |
Tokyo |
|
JP |
|
|
Assignee: |
Konica Minolta, Inc.
Tokyo
JP
|
Family ID: |
55696839 |
Appl. No.: |
15/015544 |
Filed: |
February 4, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G03G 2221/1645 20130101;
G03G 21/206 20130101; B01D 46/0045 20130101 |
International
Class: |
G03G 21/20 20060101
G03G021/20 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 25, 2015 |
JP |
2015-035337 |
Claims
1. An air cleaner having a filter, causing air from an image
forming device to pass through the filter and discharging the
filtered air, the air cleaner comprising: an air duct having an
inlet via which air from the image forming device is received and
an outlet facing a first part of a main surface of the filter and
via which the received air is output in a direction towards the
first part of the main surface; a fan causing air from the image
forming device to be received by the air duct via the inlet, to be
output from the air duct via the outlet, and to pass through the
filter; and a flow distributer disposed between the outlet and the
filter, the flow distributer changing a direction of flow of air
output from the air duct from the direction towards the first part
of the main surface to a direction towards a second part of the
main surface of the filter, the second part being a part of the
main surface that does not face the outlet.
2. The air cleaner of claim 1, wherein the air duct has a curve
between the inlet and the outlet, and a path of air flow has
greater cross-sectional area between the outlet and the main
surface of the filter than at the outlet.
3. The air cleaner of claim 1, wherein the flow distributer has a
mountain-shaped protrusion protruding towards the outlet.
4. The air cleaner of claim 3, wherein a slope of the
mountain-shaped protrusion is curved to form a concave shape.
5. The air cleaner of claim 3, wherein the mountain-shaped
protrusion has a conical shape.
6. The air cleaner of claim 5, wherein the fan takes in air from
the image forming device at a position upstream from the inlet
along the path of air flow, and discharges the air taken-in in a
direction along the main surface of the filter to be received by
the inlet, and the flow distributer has an asymmetric conical shape
with an apex thereof offset from a center of the outlet in the
direction in which air is discharged from the fan.
7. The air cleaner of claim 1 further comprising a plurality of
ribs disposed about the outlet, wherein the flow distributer is
supported by the ribs.
8. The air cleaner of claim 7, wherein the ribs are disposed
spirally about the outlet.
9. The air cleaner of claim 1, wherein the flow distributer has at
least one through hole penetrating through a main surface thereof
facing the outlet.
10. An image forming device comprising: the air cleaner of claim
1.
11. The image forming device of claim 10, wherein the air cleaner
is disposed at a rear side of the image forming device.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on application No. 2015-035337
filed in Japan, the contents of which are hereby incorporated by
reference.
BACKGROUND
[0002] (1) Field of the Invention
[0003] The present disclosure is related to an air cleaner that
takes in air discharged from a fixing device and the like included
in an image forming device such as a printer, a copier, or a
multifunctional peripheral (MHP), causes the air from the fixing
device and the like to pass through a filter, and discharges the
filtered air.
[0004] (2) Related Art
[0005] Conventionally, a fixing device, etc., included in an image
forming device such as a printer or a copier may generate
undesirable airborne substances such as volatile organic compounds
(VOCs) and the like. Such undesirable airborne substances, when
discharged to the outside of the image forming device, may
negatively affect office environment. Thus, in order to achieve a
comfortable office environment, a conventional image forming device
is provided with a mechanism that takes in air from the image
forming device, which contains the undesirable airborne substances
discharged from the fixing device, etc., causes the air from the
image forming device to pass through a filter, and discharges the
filtered air.
[0006] Such a mechanism is commonly referred to as an air cleaner,
and typically includes, in addition to a filter, a discharge fan
and an air duct.
[0007] Recently, more interest is being directed to maintaining a
clean office environment. This trend gives rise to the necessity of
improving filter performance of air cleaners and thereby reducing
the amount of undesirable airborne substances discharged to the
outside of image forming devices to as small an amount as possible.
Filter performance may be improved, for example, by increasing
filter surface area and filter thickness. However, increasing
filter thickness unfortunately brings about an increase in
depth-direction length of image forming devices, which results in
inefficient use of office space. As such, typically, filter surface
is increased to improve filter performance.
[0008] For example, Japanese Patent Application Publication No.
2002-014583 (referred to in the following as Patent Literature 1)
discloses one example of a technology for achieving such an
improvement in filter performance without increasing the overall
size of an image forming device. In specific, Patent Literature 1
discloses an air cleaner (a dust removing device) that has a
pleated filter (i.e., a pleats part 6) that achieves both compact
size and increased filter surface area. In addition, Patent
Literature 1 discloses a structure where a cross-sectional area of
an air flow path in the air cleaner, which guides air from the
image forming device containing undesirable airborne substances to
the filter, increases considerably upon reaching an inlet of a part
where the filter (i.e., the pleats part 6) is accommodated, and
where the inlet and the filter are located close to one
another.
[0009] Accordingly, the air cleaner disclosed in Patent Literature
1 improves filter performance without increasing overall image
forming device size.
[0010] Meanwhile, as described above, Patent Literature 1 discloses
a structure where the air flow path in the air cleaner expands
considerably upon reaching the inlet of the part where the filter
is accommodated, and where the inlet and the filter are located
close to one another. This structure causes air containing
undesirable airborne substances, upon being taken in to the part
where the filter is accommodated via the inlet, to be mainly guided
towards an area of the filter that faces the inlet, before
spreading over the entirety of the surface of the filter. This
results in the filter capturing the undesirable airborne substances
mainly at an area thereof facing the inlet, which then results in a
decrease of filter performance (i.e., the ability of capturing
undesirable airborne substances) occurring at a faster rate at the
area facing the inlet than at other areas of the filter. As a
result, filter clogging is accelerated at the area facing the
inlet, which shortens filter lifetime.
[0011] In view of such technical problems, the present disclosure
aims to provide an air cleaner that suppresses a local decrease in
filter performance, and an image forming device including such an
air cleaner.
SUMMARY
[0012] To achieve at least one of the abovementioned aims, an air
cleaner reflecting one aspect of the present disclosure is an air
cleaner having a filter, causing air from an image forming device
to pass through the filter and discharging the filtered air, the
air cleaner including: an air duct having an inlet via which air
from the image forming device is received and an outlet facing a
first part of a main surface of the filter and via which the
received air is output in a direction towards the first part of the
main surface; a fan causing air from the image forming device to be
received by the air duct via the inlet, to be output from the air
duct via the outlet, and to pass through the filter; and a flow
distributer disposed between the outlet and the filter, the flow
distributer changing a direction of flow of air output from the air
duct from the direction towards the first part of the main surface
to a direction towards a second part of the main surface of the
filter, the second part being a part of the main surface that does
not face the outlet.
[0013] In the air cleaner reflecting one aspect of the present
disclosure, it is desirable that the air duct have a curve between
the inlet and the outlet, and a path of air flow have greater
cross-sectional area between the outlet and the main surface of the
filter than at the outlet.
[0014] In the air cleaner reflecting one aspect of the present
disclosure, it is desirable that the flow distributer have a
mountain-shaped protrusion protruding towards the outlet.
[0015] The air cleaner reflecting one aspect of the present
disclosure desirably further includes a plurality of ribs disposed
about the outlet, and it is desirable that the flow distributer be
supported by the ribs.
[0016] In the air cleaner reflecting one aspect of the present
disclosure, it is desirable that the flow distributer have at least
one through hole penetrating through a main surface thereof facing
the outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] These and other objects, advantages and features of the
invention will become apparent from the following description
thereof taken in conjunction with the accompanying drawings those
illustrate a specific embodiment of the invention.
[0018] In the drawings:
[0019] FIG. 1 is a perspective view illustrating the exterior of an
image forming device 1 pertaining to an embodiment;
[0020] FIG. 2 is a cross-sectional view illustrating the structure
of the image forming device 1;
[0021] FIG. 3 is a perspective view illustrating the relationship
between a fixing device 40, a paper ejector 80, and an air cleaner
90;
[0022] FIG. 4 illustrates a state where the air cleaner 90 has been
detached from the paper ejector 80;
[0023] FIG. 5 is a magnified perspective view illustrating the
detailed structure of a fan 901 and an air duct 902;
[0024] FIG. 6 is a perspective view illustrating ribs 9021 and an
air flow distributer 903, as seen from a position upstream than an
outlet 902B of the air duct 902 in a direction in which air flows
in the air cleaner 90;
[0025] FIG. 7 is an exploded perspective view illustrating the ribs
9021 and the air flow distributer 903, as seen from a position
downstream than the outlet 902B of the air duct 902 in the
direction in which air flows in the air cleaner 90;
[0026] FIG. 8 is a schematic illustrating air flow from the air
duct 902 to an electrostatic filter 904, when the air flow
distributer 903 is implemented by using a member whose portion
facing the outlet 902B has a flat, circular disc shape;
[0027] FIG. 9 is a schematic illustrating air flow from the air
duct 902 to the electrostatic filter 904, when the air flow
distributer 903 is implemented by using a member whose portion
facing the outlet 902B has a symmetric conical shape; and
[0028] FIG. 10 is a schematic illustrating air flow from the air
duct 902 to the electrostatic filter 904, when the air flow
distributer 903 is implemented by using a member whose portion
facing the outlet 902B has an asymmetric conical shape.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0029] The following describes an image forming device pertaining
to one embodiment of the present disclosure, with reference to the
accompanying drawings.
[1] Structure of Image Forming Device
[0030] FIG. 1 is a perspective view illustrating the exterior of
the image forming device pertaining to the present embodiment
(image forming device 1). The image forming device 1 is a
multifunctional peripheral (MFP). The image forming device 1
includes an operation panel 60, an air cleaner (not depicted in
FIG. 1), and an image reader 70. The operation panel 60 is located
at a front side of the image forming device 1, which is indicated
by arrow A in FIG. 1. The air cleaner is located at a rear side of
the image forming device 1, which is indicated by arrow B in FIG.
1. The image reader 70 is located above the housing of a main part
of the image forming device 1.
[0031] FIG. 2 is a cross-sectional view illustrating the structure
of the image forming device 1, which forms images by using the
electro-photographic method. As illustrated in FIG. 2, the image
forming device 1 includes, in addition to the operation panel 60
and the image reader 70, an image processing unit 10; a paper
feeder 30; a fixing device 40; and a control unit 50.
[0032] The image forming device 1 is connected to a network, such
as a LAN. When receiving a print instruction from an external
terminal device (not depicted in any of the drawings) or from the
operation panel 60, the image forming device 1 performs printing
onto a recording sheet in response to the print instruction by
forming toner images of the respective colors yellow, magenta,
cyan, and black, and transferring all of the toner images so as to
be overlaid on one another on the recording sheet. In the following
and in the drawings, the colors yellow, magenta, cyan, and black
are respectively indicated by using the alphabets Y, M, C, and K.
Further, in the following and in the drawings, constituent elements
of the respective colors (e.g., image formers of the respective
colors) are distinguished from one another by adding the alphabets
Y, M, C, and K to reference numbers.
[0033] The image processing unit 10 includes: image formers 10Y,
10M, 10C, 10K; an intermediate image transfer belt 21; and a
secondary image transfer roller 27. The image formers 10Y, 10M,
10C, 10K have identical structures, and thus, are described in the
following by focusing on the image former 10Y as one example.
[0034] The image former 10Y includes: a photosensitive drum 11; a
charger 12; an exposure unit 13; a developer 14; and a cleaner 15.
The charger 12, the exposure unit 13, the developer 14, and the
cleaner 15 are disposed around the photosensitive drum 11. The
image former 10Y forms a toner image of color Y on the
photosensitive drum 11. The charger 12 charges a circumferential
surface of the rotating photosensitive drum 11, and the cleaner 15
cleans the photosensitive drum 11.
[0035] The exposure unit 13 includes light-emitting elements such
as laser diodes. Upon receiving a drive signal from the control
unit 50, the exposure unit 13 emits a laser L for forming an image
of the color Y, and exposes the charged circumferential surface of
the photosensitive drum 11 to the laser L. Thus, an electrostatic
latent image is formed on the photosensitive drum 11.
[0036] The developer 14 faces the photosensitive drum 11, and
carries toner to the photosensitive drum 11. The intermediate
transfer belt 21 is an endless belt that is suspended in tension
state across a drive roller 24 and a pair of driven rollers 25, 26,
and is driven to rotate in the direction indicated by arrow C in
FIG. 1. An electrostatic latent image having been formed on each
photosensitive drum (i.e., photosensitive drums of the image
formers 10Y, 10M, 10C, 10K) is developed by the developer in the
same image former, whereby an unfixed toner image of the
corresponding color is formed on the photosensitive drum.
[0037] The toner images formed on the photosensitive drums undergo
primary transfer by primary transfer rollers provided in one-to-one
correspondence with the image formers, and thus are transferred
onto the intermediate transfer belt 21. Note that in FIG. 1, only
the primary transfer roller corresponding to the image former 10Y
is explicitly indicated by being provided with the reference number
22. Here, the primary transfer of the toner images formed on the
respective photosensitive drums is performed such that the toner
images are transferred at different timings onto the intermediate
transfer belt 21 so as to be overlaid one on top of another on the
same position of the intermediate transfer belt 21. Subsequently,
the electrostatic force applied by the secondary transfer roller 27
causes the toner images on the intermediate transfer belt 21 to
undergo secondary transfer, such that the toner images are
transferred all at once onto a recording sheet.
[0038] The paper feeder 30 includes: a paper supply cassette 31; a
feed roller 32; a transport roller pair 33; and a timing roller
pair 34. The paper supply cassette 31 accommodates a plurality of
recording sheets, one of which is indicated by reference sign S in
FIG. 1. The feed roller 32 feeds the recording sheets S onto a
sheet transport path, one at a time. The transport roller pair 33
transports the recording sheet S along the sheet transport
path.
[0039] The timing roller pair 34 transports the recording sheet S
to a position 28 where the secondary transfer takes place so that
the recording sheet S and the toner images overlaid on the same
position of the intermediate transfer belt 11 through primary
transfer arrive at the position 28 at the same time. As already
discussed above, at the position 28, the secondary transfer roller
27 causes the toner images on the intermediate transfer belt 21 to
undergo secondary transfer, such that the toner images are
transferred all at once onto the recording sheet S.
[0040] The fixing unit 40 includes: a fixing roller 41; a heating
roller 42; a fixing belt 43; and a pressing roller 44. Here, as one
example, the heating roller is heated by a halogen heater. The
fixing belt 43 is suspended in tension state across the fixing
roller 41 and the heating roller 42. The pressing roller 44 forms a
fixing nip by pressing on the fixing roller 41 with the fixing belt
43 in between. The fixing unit 40, at the fixing nip, applies heat
and pressure to the recording sheet S carrying the toner images
having been transferred thereon through the secondary transfer, and
thereby heat-fixes the toner images onto the recording sheet S.
[0041] The above-described components of the fixing unit 40 (i.e.,
the fixing roller 41, the heating roller 42, the fixing belt 43,
and the pressing roller 44) are housed inside a housing 45 of the
fixing unit 40. The housing 45 has undepicted slits (openings)
formed therein, one at each side thereof in the direction along
which the recording sheet S is transported thereto. The slits are
for letting the recording sheet S in and out of the housing 45.
[0042] The recording sheet S carrying the heat-fixed image is
transported to an eject roller pair 81 via a paper ejector (the
paper ejector is described in detail later in the present
disclosure). Further, the recording sheet S is ejected onto an
eject tray 82 by the eject roller pair 81.
[0043] The control unit 50 is a so-called computer, and includes a
central processing unit (CPU), a read-only memory (ROM), and a
random access memory (RAM). The control unit 50 has overall control
over the image forming device 1. The operation panel 60 includes a
liquid crystal display, a touch panel laminated on the liquid
crystal display, and one or more operation buttons allowing input
of various instructions. The operation panel 60 receives input of
instructions from a user when the user operates the touch panel,
the operation buttons, etc., provided to the operation panel 60.
The image reader 70 includes an image input device such as a
scanner. The image reader 70 reads information from a recording
sheet (e.g., a sheet of paper). The information is related to one
or more images printed on the recording sheet. The images may be
images of characters, shapes, and photographs appearing on the
recording sheet. Further, by using the information read from a
recording sheet, the image reader 70 generates image data.
[2] Structure of Air Cleaner
[0044] FIG. 3 is a perspective view illustrating the relationship
between the fixing device 40, a paper ejector 80, and an air
cleaner 90. As illustrated in FIG. 3, the air cleaner 90 includes:
a fan 901; an air duct 902; an air flow distributer 903; and an
electrostatic-type filter 904 (referred to in the following as the
"filter 904"). Note that the filter 904 is implemented by using an
electrostatic-type filter having a pleated shape. Thus, the main
surface of the filter 904 has greater surface area than a main
surface of an electrostatic-type filter not having a pleated shape.
Further, the air cleaner 90 can be attached to and detached from
the paper ejector 80, as illustrated in FIG. 4. Specifically, as
illustrated in FIG. 4, the air cleaner 90 can be attached to the
paper ejector 80 by causing an engagement portion 9010 provided to
the fan 901 to engage with an outlet of a duct 801 of the paper
ejector 80, and thereby connecting the fan 901 to the outlet of the
duct 801. The engagement portion 9010 is provided with a
rectangular opening that allows the engagement portion 9010 to
engage with the outlet of the duct 801.
[0045] Referring to FIG. 3 once again, the fan 901 is provided at
an entrance portion of the air cleaner 90, and is connected to the
outlet of the duct 801.
[0046] FIG. 5 is a magnified perspective view illustrating the
structure of the fan 901 and the air duct 902 in detail. As
illustrated in FIG. 5, the fan 901 is a centrifugal fan (sirocco
fan), and includes: a blower wheel 901A having a plurality of
blades; a casing 901B; and a fan motor 901C. The fan 901 causes air
from a main body of the image forming device 1, which includes the
fixing device 40 and the surrounding of the fixing device 10, to
enter the duct 801 (illustrated in FIG. 3) from an undepicted inlet
provided to the duct 801. Note that the air from the main body of
the imaging forming device 1 contains atmospheric air and
undesirable airborne substances generated at the fixing device 40
and the surrounding of the fixing device 40. Further, the fan 901
takes in the air having entered the duct 801 towards a rotation
axis thereof (in the direction illustrated by dotted arrow E in
FIGS. 3 and 5) and discharges the air in a direction along the main
surface of the filter 904 (the direction illustrated by dotted
arrow F in FIGS. 3 and 5), due to centrifugal force caused by
rotation so that the air arrives at the inlet of the air duct
902.
[0047] As illustrated in FIGS. 3 and 5, the air duct 902 has a
curve between the inlet and an outlet 902B, and faces the main
surface of the filter 904 at the outlet 902B. The air duct 902
connects to the inside of a housing 905, which houses the filter
904. Further, as illustrated in FIGS. 5, 6, and 7, ribs 9021 are
disposed spirally about the outlet 902B. The ribs 9021 support the
air flow distributer 903. The air flow distributer 903 is described
in detail later in the present disclosure.
[0048] FIG. 6 is a perspective view illustrating the ribs 9021 and
the air flow distributer 903, as seen from a position upstream than
the outlet 902B in a direction in which air flows in the air
cleaner 90. FIG. 7 is an exploded perspective view illustrating the
ribs 9021 and the air flow distributer 903, as seen from a position
downstream than the outlet 902B in the direction in which air flows
in the air cleaner 90.
[0049] In specific, FIG. 7 is an exploded perspective view
illustrating how the ribs 9021 are formed about the outlet 902B,
which is formed in an outlet part member of the air duct 902.
Further, FIG. 7 illustrates how the ribs 9021 support the air flow
distributer 903, and illustrates that a portion of the air flow
distributer 903 facing the outlet 902B has an asymmetric conical
shape.
[0050] The ribs 9021 are formed spirally, to conform to a direction
in which air discharged from the outlet 902B whirls. Here, note
that the air flow distributer 903 may either be adhered to the ribs
9021 or integrally formed with the ribs 9021.
[0051] Meanwhile, it is also possible to fix the position of the
air flow distributer 903 inside the housing 905 without providing
the ribs 9021. However, providing the ribs 9021 allows effectively
guiding air discharged from the outlet 902B to the air flow
distributer 903 along the ribs 9021. Thus, providing the ribs 9021
reduces pressure loss of air discharged from the outlet 902B and
improves discharge efficiency compared to not providing the ribs
9021.
[0052] Returning to FIG. 3 once again, the air taken-in to the air
duct 902 leaves the air duct 902 via the outlet 902B, and enters
the housing 905 by flowing along the portion of the air flow
distributer 903 facing the outlet 902B. The air flow distributer
903 is disposed between the outlet 902B and the filter 904. As
already described above, the housing 905 houses the filter 904.
Thus, the undesirable airborne substances contained in the air from
the main body of the image forming device 1 are captured at the
filter 904, before being discharged to the outside.
[0053] Accordingly, the air from the main body of the image forming
device 1 is prevented from directly reaching an area of the main
surface of the filter 904 facing the outlet 902B, from the outlet
902B. That is, a direction in which the air discharged from the
outlet 902B flows is changed so that the air spreads over the
entirety of the main surface of the filter 904 without intensively
flowing towards the area of the main surface of the filter 904
facing the outlet 902B.
[0054] Here, it should be noted that the portion of the air flow
distributer 903 facing the outlet 902B may have any shape as long
as capable of changing the direction of flow of the air discharged
from the outlet 902B to spread over the entirety of the main
surface of the filter 904. For example, the portion of the air flow
distributer 903 facing the outlet 902B may have any one of the
shapes illustrated in FIGS. 8, 9, 10.
[0055] FIG. 8 is a schematic illustrating air flow from the air
duct 902 to the filter 904 when the portion of the air flow
distributer 903 facing the outlet 902B has a flat plate-like shape
(in FIG. 8, the portion of the air flow distributer 903 facing the
outlet 902B has a circular disk-like shape). In FIG. 8, reference
symbols 901, 902, 902A, 902B, 903, 904, and 905 respectively
indicate the fan, the air duct, the inlet of the air duct, the
outlet of the air duct, the air flow distributer, the filter, and
the housing. Further, in FIG. 8, air flow is indicated by using
arrows, and the white arrow indicated by reference symbol F
indicates the direction in which the air is discharged from the fan
901 to the air duct 902. The above explanations similarly apply to
each of FIGS. 9 and 10.
[0056] As illustrated in FIG. 8, the air guided to the outlet 902B
collides with and spreads along the flat surface of the portion of
the air flow distributer 903 facing the outlet 902B, thereby
spreading over the entirety of the surface of the filter 904.
Although not illustrated in FIG. 8, it should be noted that due to
collision with the inner wall of the housing 905, the surface of
the filter 904, etc., and the consequent change in flow direction,
some of the air also reaches the area of the filter 904 facing a
rear surface of the air flow distributer 903, however smaller the
amount of the air reaching this area of the filter 904 may be than
the amount of the air reaching other areas of the filter 904. This
similarly applies to each of FIGS. 9 and 10, description related to
which is provided in the following.
[0057] FIG. 9 is a schematic illustrating air flow from the air
duct 902 to the filter 904 when the portion of the air flow
distributer 903 facing the outlet 902B has a symmetrical conical
shape. Similar to the configuration illustrated in FIG. 8, in the
configuration illustrated in FIG. 9, the air guided to the outlet
902B collides with and spreads along the inclined lateral surface
of the conical portion of the air flow distributer 903 facing the
outlet 902B, thereby spreading over the entirety of the main
surface of the filter 904. In addition, providing the portion of
the air flow distributer 903 facing the outlet 902B with a conical
shape reduces pressure loss of the air discharged from the outlet
902B compared to when the portion has a flat surface, and thereby
improves discharge efficiency, due to the air discharged from the
outlet 902B being distributed to the entirety of the main surface
of the filter 904 through collision with the inclined lateral
surface of the conical portion of the air flow distributer 903
facing the outlet 902B.
[0058] FIG. 10 is a schematic illustrating air flow from the air
duct 902 to the filter 904 when the portion of the air flow
distributer 903 facing the outlet 902B has an asymmetric conical
shape. Here, the flow distributer 903 is disposed such that the
apex of the conical portion facing the outlet 902B is offset in the
direction F, in which the air is discharged from the outlet 902B,
with respect to the center of the outlet 902B (i.e., with respect
to the apex of the conical portion of the flow distributor 903
illustrated in FIG. 9). Similar to the configuration illustrated in
FIG. 9, in the configuration illustrated in FIG. 10, the air guided
to the outlet 902B collides with and spreads along the inclined
lateral surface of the conical portion of the air flow distributer
903 facing the outlet 902B, thereby spreading over the entirety of
the main surface of the filter 904. In addition, providing the
portion of the air flow distributer 903 facing the outlet 902B with
a conical shape reduces pressure loss of the air discharged from
the outlet 902B compared to when the portion has a flat surface,
and thereby improves discharge efficiency, due to the air
discharged from the outlet 902B being distributed to the entirety
of the main surface of the filter 904 through collision with the
inclined lateral surface of the conical portion of the air flow
distributer 903 facing the outlet 902B.
[0059] In addition, in the configuration illustrated in FIG. 10, a
portion of the inclined lateral surface of the conical portion of
the air flow distributer 903 that extends from the apex towards the
direction opposite the direction F (referred to in the following as
reverse-direction inclined surface portion) has greater surface
area than a portion of the inclined lateral surface of the conical
portion of the air flow distributer 903 that extends from the apex
towards the discharge direction F (referred to in the following as
forward-direction inclined surface portion). Accordingly, the air
discharged from the outlet 902B is more likely to be guided towards
the reverse-direction inclined surface portion than towards the
forward-direction inclined surface portion. Thus, the air flow
distributer 903 is capable of changing the direction of air flow so
that air flow is not biased towards the discharge direction F.
[0060] Here, it should be noted that the air is discharged from the
outlet 902B towards the discharge direction F. Thus, when surface
area of the reverse-direction inclined surface portion is equal to
the surface area of the forward-direction inclined surface portion,
the amount of the discharged air arriving at the forward-direction
inclined surface portion would be greater than the amount of the
discharged air arriving at the reverse-direction inclined surface
portion. This results in the amount of undesirable airborne
substances captured differing between an area of the main surface
of the filter 904 that is located in the discharge direction F from
the area of the main surface of the filter 904 facing the outlet
902B and an area of the main surface of the filter 904 that is
located in the direction opposite the discharge direction F from
the area of the main surface of the filter 904 facing the outlet
902B.
[0061] In view of this, providing the portion of the air flow
distributer 903 facing the outlet 902B with an asymmetric conical
shape as illustrated in FIG. 10 suppresses such difference in the
amount of undesirable airborne substances captured by different
areas of the filter 904. This further prevents a difference in
filter performance occurring between different areas of the filter
904.
[0062] As such, in the present embodiment, the distance between the
outlet 902B of the air duct 902 and where the filter 904 is located
in the housing 905 is relatively small. Further, the air cleaner 90
has an air flow path having greater cross-sectional area in the
housing 905, into which the air discharged from the outlet 902B is
input, than at the outlet 902B, and the air flow distributer 903 is
disposed between the outlet 902B and the filter 904, near a
downstream side of the outlet 902B in the direction of air flow. As
already described above, the air flow distributer 903 distributes
the air discharged from the outlet 902B by changing the direction
of air flow. Due to this, the direction of air flow from the outlet
902B into the housing 905B is changed so that air flow is not
intensified towards the area of the main surface of the filter 904
facing the outlet 902B and the discharged air arrives at areas of
the main surface of the filter 904 other than the area facing the
outlet 902B.
[0063] This prevents a rapid decrease in filter performance from
occurring at the area of the main surface of the filter 904 facing
the outlet 902B. Thus, clogging of the area of the main surface of
the filter 904 facing the outlet 902B is suppressed, and, a
shortening of lifetime of the filter 904 is prevented. That is, the
present embodiment suppresses a local decrease in filter
performance, and thereby extends the lifetime of the filter
904.
(Modifications)
[0064] In the above, the technology pertaining to the present
disclosure is described based on a specific form of embodiment
thereof. However, needless to say, the embodiment merely provides a
non-limiting example of how the technology pertaining to the
present disclosure may be implemented, and it should be construed
that the present disclosure encompasses in the spirit and scope
thereof, for example, the modifications described in the
following.
[0065] (1) In the embodiment, a conical shape is discussed as one
specific example of a shape of the portion of the air flow
distributer 903 facing the outlet 902B that reduces pressure loss
occurring when the air comes in contact with the air flow
distributer 903. However, as long as the air flow distributer 903
is capable of reducing such pressure loss, the portion of the air
flow distributer 903 facing the outlet 902B may have any shape
forming a mountain-shaped protrusion, such as a pyramid shape, a
frustum shape, and a circular truncated cone shape.
[0066] When making such a modification, in order to achieve a
further reduction in pressure loss, a slope of the mountain-shaped
protrusion may be curved to form a concave shape.
[0067] (2) The portion of the air flow distributer 903 facing the
outlet 902B may have one or more through-holes formed therein. This
allows the air discharged from the outlet 902B to reach the area of
the main surface of the filter 904 that faces the rear surface of
the air flow distributer 903 (i.e., a portion of the air flow
distributer 903 not facing the outlet 902B). This reduces a
difference in the amount of air flow reaching the area of the main
surface of the filter 904 facing the rear surface of the air flow
distributer 903 and the amount of air flow reaching other areas of
the main surface of the filter 904. Accordingly, the risk is
reduced of a difference in filter performance occurring between the
area of the main surface of the filter 904 facing the rear surface
of the air flow distributer 903 and other areas of the main surface
of the filter 904.
[0068] (3) In the embodiment, the filter 904 is implemented by
using an electrostatic-type filter having a pleated shape. However,
needless to say, the air flow distributer 903 pertaining to the
embodiment is usable in combination with other filters, including
electrostatic-type filters not having a pleated shape and filters
of types other than the electrostatic-type.
[0069] Although the present invention has been fully described by
way of examples with reference to the accompanying drawings, it is
to be noted that various changes and modifications will be apparent
to those skilled in the art.
[0070] Therefore, unless otherwise such changes and modifications
depart from the scope of the present invention, they should be
construed as being included therein.
* * * * *